1. Field of the Invention
A machine for carrying out air seal tests on wheel rims for vehicles. The machine checks possible porosities, which can be passing, diffused or situated in walls of the wheel rims obtained by casting.
2. History of the Related Art
Up to now, the tests for seal of the wheel rims for vehicles obtained by casting, to be used on wheels without an inner tube (tubeless), have been carried out following two different principles. In both, the inner volume of the rim was isolated from the environment, by means of special sealing surfaces. The set, including the rim and sealing surfaces, was introduced into a water volume, and air, at a volume of high pressure, was let into the inner volume defined by the rim. Therefore, it was possible to verify the presence of possible small bubbles indicating the incorrect seal of the rim's walls. The inconveniences of this system are based on the fact that the inspection was entrusted to a controller, and further, that is was not possible to quantify the value of the loss and the pressure is exerted in a sense opposite to the normal operation pressure which is from the outer area of the rim. Another inspection system consists in introducing gas, at a high pressure, into a chamber exterior to the rim and then inspecting the possible variation of gas pressure in the inner isolated chamber of the rim. This system presents the problem of the difficult identification of the pressure variation in the inner chamber, which is very limited, because of the considerable volume of the inner chamber.